Our 05 Ascender got switched at the 2k mark. It has syn in it anyways. It didn’t have a break in period at all, but the oil that was in it was different. It had a much different texture to it than I ever remember feeling. I assume that oil is a type of break in oil.
But we did call before switching. We where told that first we can switch with no chance of warranty problems. Secondly about the break in oil. That the break in so to speak is done at the factory. It doesn’t matter if you drain the oil when you get the car, its already done its job.
How it’s different from your standard oil or syn I can’t explain. But the feel was different. Seemed more slick than normal, and had a red tint to it.